Phototherapy apparatus and method for bone healing, bone growth stimulation, and bone cartilage regeneration

ABSTRACT

Phototherapy apparatus, incorporating interconnected radiation sources, such as diode laser cluster radiation devices, and method for bone healing, bone growth stimulation, and bone cartilage regeneration are disclosed. The method consists of applying the said radiation cluster apparatus conformally around the desired area of the bone to be treated and providing irradiation at appropriate wavelengths and power densities for a selected period of time to the said area of the bone structure to be treated. The apparatus incorporates a sufficient number of the diode laser cluster devices, or other appropriate light sources, which are adapted to be placed inside an appropriate brace (e.g., ankle brace or knee brace), or are embedded inside a reconfigurable foam, or are embedded inside deformable gel material, or are embedded within the cast, which facilitate radially-positioned sources for irradiation of the area to be treated.

FIELD OF THE INVENTION

The present invention relates generally to phototherapy and inparticular to a phototherapy apparatus and method for bone healing, bonegrowth stimulation, and bone cartilage regeneration.

BACKGROUND OF THE INVENTION

The use of phototherapeutic treatment employing low-intensityirradiation has been widely demonstrated to offer benefits in thetreatment of various physiological problems and dermatologicalconditions, such as, but not limited to, carpal tunnel syndrome,tendonitis, bone growth and regeneration, rheumatoid arthritis, woundhealing, acne, and general pain control. Phototherapeutic treatmenttypically affects photoreceptors in the tissue, with consequentalterations in the biochemical processes of the cells. This isaccompanied by an increase in local blood circulation and astrengthening of the immune defense system.

In the past several decades, it was also demonstrated that phototherapyis effective in promoting healing of bone, muscle, cartilage, tendon,and ligament. The mechanism in such treatments typically relates to theprocess of absorption of photons by mitochondria, followed by adenosinetriphosphate (ATP) synthesis, which then influences the synthesis ofsuch biological species as proteins, enzymes, DNA/RNA that are requiredfor cell repair or regeneration and for promotion of cell proliferation.

Thus, to summarize briefly, it is widely accepted that absorbed lighttriggers biological changes within the body, and in such cases, the useof specific wavelengths of light accelerates cellular metabolicprocesses and stimulates vital chemical reactions. Specifically,phototherapy can (i) increase the circulation by promoting the formationof new capillaries, which accelerate the healing process, (ii) increaseDNA/RNA synthesis, which assists damaged cells to be replaced morerapidly, (iii) stimulate collagen protein production, which is importantfor repairing damaged tissue and replacing old tissue, and (iv)stimulate the release of adenosine triphosphate (ATP) that is a majorcarrier of energy to cells.

It is important to note that the optical window of the skin, (i.e., awavelength range with an optimal transmission of light) is in the rangebetween about 600 nm and 1300 nm. Wavelengths, shorter or longer thanthat range are generally absorbed before reaching substantial depth.

In the case of bone growth and healing, the effect of low level lasertherapy (LLLT) on bone regeneration relates to biostimulation of thetissues with monochromatic light. The LLLT has been shown to promotecollagen production, accelerate cell proliferation, and enhance bonehealing.

The various applications of phototherapy were outlined in variouspublications, some of which are listed in the References list (see, forexample, The science of low-power laser therapy by Karui). It is thoughtthat a low level optical radiation induces biostimulation related tophotochemical and photophysical processes on the molecular and cellularlevels.

The phototherapy efficacy is related to several major factors. Theseinclude spectral range, irradiance (i.e., power per surface area perwavelength), exposed surface area, choice of pulsing frequency, andexposure duration.

Typically, in phototherapy, a careful selection of the spectral contentof light used for treatment is required. There were numerous studiesconfirming the importance of selecting a specific wavelength forphototherapy treatment to be optimal. For example, in the cases oftreating wounds, such wavelengths include 680, 730 and 880 nm (Whelan,H. T. et al. J. Clin. Laser Med. Surg., vol. 19, No. 6, 305-314, 2001).

In recent years, numerous reports also clearly demonstrated thebeneficial effects of laser phototherapy on bone regeneration and bonefractures. These effects are outlined by Tuner and Hode in “The LaserTherapy Handbook”.

In the studies on bone regeneration, Pinheiro concluded that the use ofLLLT at 830 nm substantially improved bone healing at early stages.

Ueda and Shimizu, in the paper entitled “Pulse irradiation of low-powerlaser stimulates bone nodule formation”, demonstrated the effect oflower-power GaAIAs laser irradiation (830 nm, 500 mW) on acceleration ofbone formation as a function of pulse frequency, and concluded thatpulsed laser irradiation substantially stimulates bone formation andthat pulse frequency is an important factor in bone formation.

De Souza Merli et al., in the paper entitled “Effect of Low-IntensityLaser Irradiation on the Process of Bone Repair”, also showed that theuse of low-intensity GaAlAs laser has beneficial effect on bone repair.

In relation to the foregoing discussion, note that visible, especiallyred and infrared light have been demonstrated to influence many changesat a cellular level. In general, the various tissue and cell types havetheir own specific light absorption characteristics. In other words,they absorb light at specific wavelengths only. For typically employedwavelength range of 600 to 900 nm, the radiation is absorbed closer tothe surface for shorter wavelengths, whereas for longer wavelengths thepenetration depth is greater.

In relation to providing therapy to such musculoskeletal system problemsas nonunion fractures, spinal fusion, tendon injuries, and osteoporosis,in recent years, several bone stimulation methods for healing weredeveloped (see for example a paper entitled “Enhancement of fracturehealing with bone stimulators” by Anglen). Such bone stimulators forpromotion of healing typically employ electromagnetic field orultrasonic signal applied to the bone.

There are different types of electromagnetic field methods used forpromoting healing of nonunion bone fractures (i.e., those that do notheal naturally). These include pulsed electromagnetic fields (PEMFs) anddirect current methods. These therapy methods to promote healing ofnonunion bone fractures were approved by the U.S. Food and DrugAdministration (FDA).

Although the advantages of PEMF treatment are well established, ingeneral, the potential hazards of overexposure to electromagnetic fieldsare widely debated and being explored by various regulatory governingbodies.

Various studies have indicated that electromagnetic fields may posepotential health hazards in such cases of patients as (i) those withcardiac pacemakers or other implanted electrical device, (ii) those withmetallic clips and implants, (iii) those who received a localizedcortisone injection in the past several weeks, and (iv) pregnant women.

Thus, in relation to the foregoing discussion, it is desirable toprovide an apparatus and a method that do not produce such potentialhealth hazards and have a capability of a relatively simpler and moreeconomical means of therapy with fewer risks and harnnful effects, andtherefore providing a safer alternative to electromagnetic field methodsused in promoting healing of bone fractures.

It is therefore an object of the present invention to provide a novelphototherapy apparatus and method for stimulating bone growth andhealing and bone cartilage regeneration.

SUMMARY OF THE INVENTION

Accordingly, in one aspect there is provided a phototherapy apparatuscomprising:

a support adapted to overlie and conform generally to a region of apatient to be treated; and

a plurality of radiation sources disposed on said support, eachradiation source including at least one radiation emitting device toemit radiation to promote bone healing, bone growth stimulation and bonecartilage regeneration.

In one embodiment, each radiation source includes a plurality ofradiation emitting devices. The radiation emitting devices are selectedfrom the group consisting of laser diodes, light emitting diodes,thin-film electroluminescent devices, fiber-optic delivery systemsand/or bandages incorporating nanocrystals that emit radiation atpredetermined wavelengths in response to excitation. The radiationsources are arranged radially about the support. The radiation sourcesmay be operated in one of a continuous and pulsed manner.

The radiation emitted by the radiation sources has a wavelength selectedfor the penetration of biological tissue and transmission to bonetissue. The support in one embodiment is a flexible brace adapted tosurround and conform to the region of a patient to be treated. Inanother embodiment, the support is a cast or a deformable gel material.In this case, the radiation sources are embedded therein.

The phototherapy apparatus may further include a controller to controloperation of the radiation sources to enable the radiation to be emittedin a desired pattern. A display may be provided to display phototherapyprocedures and/or treatment protocols.

In another embodiment, the radiation emitting devices are accommodatedby gimbal-type supports. In this manner, emitted radiation is collimatedwithin a variable solid angle centered on the targeted area.

According to another aspect of the present invention there is provided aphototherapy method. A region of a patent to be treated is overlayedwith the phototherapy apparatus described above. Irradiation atappropriate wavelengths and power densities is provided for a selectedperiod of time to the area of the bone structure to be treated.

The radiation generated by the apparatus can be augmented with differenttypes of electromagnetic field methods used for promoting healing ofnonunion bone fractures.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments will now be described by way of example only, with referenceto the accompanying drawings, in which:

FIG. 1 is a schematic of a phototherapeutic apparatus for bone healing,bone growth stimulation, and bone cartilage regeneration;

FIG. 2 is a schematic of another embodiment of a phototherapeuticapparatus for bone healing, bone growth stimulation, and bone cartilageregeneration; and

FIG. 3 is an enlarged schematic of a portion of the phototherapeuticapparatus of FIG. 2.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Turning now to FIG. 1, a phototherapeutic apparatus for bone healing,bone growth stimulation, and bone cartilage regeneration is shown and isgenerally identified by reference numeral 10. As can be seen,phototherapeutic apparatus 10 includes a brace 12 that is adapted tosurround a region of a patient to be treated. In this particularexample, the brace includes a body 14 of flexible foam material. A pairof releasable clips 16 engage the ends of the body 14 to keep the brace12 in a radial configuration. The nature of the foam material allows thebrace 12 to conform to the shape of the region to be treated ensuringeffective phototherapeutic treatment.

A plurality of interconnected radiation sources 20 is disposed about theinterior surface 22 of the brace 12 at different radial locations. Eachradiation source 20 includes an array of light sources 24. In thisparticular example, each radiation source includes an array of nine (9)laser diodes. The laser diodes 24 are driven by power electronics (notshown) and a programmable controller (not shown) allowing the laserdiodes 24 to be operated either in a continuous wave (cw) mode or apulsed mode. A power supply (not shown) carried by the brace 12 providesthe necessary operating power.

The nature of the radiation emitted by the laser diodes 24 is selectedto ensure penetration of biological tissue and transmission to bonetissues. In this particular embodiment, the laser diodes 24 emitradiation having a wavelength in the range of from about 600 nm to 1300nm. Typically, the laser diodes 24 emit radiation in the range of fromabout 600 nm to 900 nm and more particularly, the range of from about800 nm to 880 nm. In this manner, when the brace 12 is worn by a patientabout the area to be treated and the radiation sources 20 are operated,the area to be treated is irradiated with light thereby to assist inbone healing, bone growth stimulation, and bone cartilage regeneration.During operation of the phototherapy apparatus 10, the radiation sources20 may be illuminated together or in a predetermined sequenceindependently of one another.

The design of the phototherapy apparatus 10 allows areas of a patientsuch as the knee, ankle, wrist, arm, elbow, spine, hip, clavicle andneck to be treated. Of course, the phototherapy apparatus 10 may be usedto treat other areas or regions of a patient.

Although not shown, the phototherapy apparatus 10 may include a displayfor displaying information relating to phototherapeutic treatmentsand/or treatment protocols. hi this manner, visual feedback is providedto the user identifying the manner in which the region being treated isbeing stimulated using radiation. Sound emitting devices and othervisual indicators can be provided to provide audible and visual feedbackconcerning treatment procedures and/or protocols.

Although the phototherapeutic apparatus 10 is described as including abrace formed of foam material, other configurations are possible. Forexample, the radiation sources 20 may be embedded inside a deformablegel material, or within a cast to be worn by a patient. Rather thanusing laser diodes, the radiation sources 20 may alternatively includelight emitting diodes, thin-film electroluminescent devices, fiber-opticdelivery systems and/or bandages incorporating nanocrystals that emitradiation at predetermined wave lengths in response to excitation fromthe control hardware and power supply.

Turning now to FIGS. 2 and 3, another embodiment of a phototherapyapparatus 50 is shown. As can be seen, the phototherapeutic apparatus 50similarly includes a brace 52 adapted to surround a region of a patientto be treated. A pair of clips 54 engage the free ends of the brace 52to maintain the brace in a radial configuration. A plurality ofradiation sources 60 is disposed about the interior surface 56 of thebrace at different radial locations.

In this embodiment, each radiation source 60 includes a single laserdiode 62. The position of the laser diode 62 is adjustable to allowradiation emitted by the radiation sources 60 to be accurately directed.In particular, each radiation source includes an upper sphericalarticulation support 64, a lever 66 facilitating precise alignment andpositioning of the laser diode, a lock screw 68 lock the laser diode 62into position, a spherical articulation 70 supporting the laser diode 62and a lower spherical articulation support 72. The upper and lowerarticulation supports 64 and 72 and the spherical articulation 70 form agimbal-type support for the laser diode 62 thereby to facilitate itsorientation.

FIG. 3 better illustrates one of the radiation sources 60 andillustrates traces of an emitted laser ray 80 and a focused laser ray82.

It can be advantageous to augment the phototherapy radiation withdifferent types of electromagnetic field methods used for promotinghealing of nonunion bone fractures, and to provide enhanced bonehealing, bone growth stimulation and bone cartilage regeneration.

Although preferred embodiments have been described, those of skill inthe art will appreciate that variations and modifications may be madewithout departing fiom the spirit and scope thereof as defined by theappended claims.

REFERENCES

-   Anglen, J. “Enhancement of Fracture Healing With Bone Stimulators”,    Techniques in Orthopaedics, 17, pp. 506-514, 2002.-   De Souza Merli, L. A., Botti Rodrigues Dos Santos, M. T.,    Genovese, W. J., and Faloppa, F., “Effect of Low-Intensity Laser    Irradiation on the Process of Bone Repair”, Photomedicine and Laser    Surgery, 23, pp. 212-215, 2005.-   Karu, T., The Science of Low-Power Laser Therapy, Gordon and Breach    Sci. Publ., 1998.-   Pinheiro, A. L. B., “Recent studies on bone regeneration”,    International Congress Series Volume 1248, pp 69-72, 2003; (Lasers    in Dentistry: Revolution of Dental Treatment in The New Millennium.    Proceedings of the 8th International Congress on Lasers in    Dentistry, held in Yokohama, Japan, between 31 July and 2 Aug.    2002).-   Trelles M., Mayayo E., “Bone Fracture Consolidates Faster with Low    Power Laser”, Lasers in Surgery and Medicine, 7, pp. 36-45, 1987.-   Tunér, J., and Hode, L., “Low Level Laser Therapy” (Clinical    Practice and Scientific Background), Prima Books, (Grangesberg,    Sweden, 1999).-   Tunér, J., and Hode, L., “The Laser Therapy Handbook”, Prima Books,    (Grangesberg, Sweden, 2004).-   Ueda Y, Shimizu N., “Pulse irradiation of low-power laser stimulates    bone nodule formation”, Journal of Oral Science 43, pp. 55-60, 2001.-   Whelan, H. T. et al., “Effect of Nasa Light-emitting Diode    Irradiation on Wound Healing”, J. Clin. Laser Med. Surg., vol. 19,    pp. 305-314, 2001.

1. A phototherapy apparatus comprising: a support adapted to overlie andconform generally to a region of a patient to be treated; and aplurality of radiation sources disposed on said support, each radiationsource including at least one radiation emitting device to emitradiation to promote bone healing, bone growth stimulation and bonecartilage regeneration.
 2. A phototherapy apparatus according to claim 1wherein each radiation source includes a plurality of radiation emittingdevices.
 3. A phototherapy apparatus according to claim 2 wherein saidradiation emitting devices are selected from the group consisting laserdiodes, light emitting diodes, thin-film electroluminescent devices,fiber-optic delivery systems, and/or bandages incorporating nanocrystalsthat emit radiation at predetermined wavelengths in response toexcitation.
 4. A phototherapy according to claim 1, wherein saidradiation sources are arranged radially about said support.
 5. Aphototherapy apparatus according to claim 1 wherein said radiationsources are operated in one of a continuous and pulsed manner.
 6. Aphototherapy apparatus according to claim 1 wherein the radiationemitted by said radiation sources has a wavelength selected for thepenetration of biological tissue and transmission to bone tissue.
 7. Aphototherapy apparatus according to claim 1 wherein said support is aflexible brace adapted to surround and conform to the region of apatient to be treated.
 8. A phototherapy apparatus according to claim 1wherein said support is one of a cast and a deformiable gel material,said radiation sources being embedded therein.
 9. A phototherapyapparatus according to claim 1 further comprising a controller tocontrol operation of the radiation sources to enable the radiation to beemitted in a desired pattern.
 10. A phototherapy apparatus according toclaim 9 further comprising a display to display phototherapy proceduresand/or treatment protocols.
 11. A phototherapy apparatus according toclaim 1 wherein each radiation emitting device is adjustably supportedby said support.
 12. A phototherapy apparatus according to claim 11wherein said radiation emitting devices are accommodated by gimbal-typesupports on said support.
 13. A phototherapy apparatus according toclaim 2 wherein said emitted radiation has a wavelength in a preselectedwavelength range based on the radiation wavelength content required fora specific therapeutic treatment.
 14. A phototherapy apparatus accordingto claim 1 wherein the emitted radiation has a in wavelength betweenultraviolet and mid-infrared.
 15. A phototherapy apparatus according toclaim 1 wherein the emitted radiation is in the range of from about 600nm to 1300 nm.
 16. A phototherapy apparatus according to claims 1wherein the emitted radiation includes visible light, or visible andinfrared light, or infrared light.
 17. A phototherapy apparatusaccording to claim 12 wherein the emitted radiation is collimated withina variable solid angle centered on the target area.
 18. A phototherapyapparatus according to claim 1 wherein the said phototherapy apparatusis combined with different types of electromagnetic field methods usedfor promoting healing of nonunion bone fractures.
 19. A phototherapymethod, comprising: overlying a region of a patient to be treated withthe apparatus of claim 1; and providing irradiation at appropriatewavelengths and power densities for a selected period of time to thesaid area of the bone structure to be treated.
 20. A phototherapy methodaccording to claim 19, further comprising: augmenting said radiationgenerated by said apparatus with different types of electromagneticfield methods used for promoting healing of nonunion bone fractures.